Non-thermal Coronal Hard X-ray Emission Observed During a Partially Occulted Flare
Abstract
We will present an analysis of RHESSI hard X-ray imaging and spectroscopy of a GOES M1.5 class flare which occurred on 1 June 2003 0210-0700 UT in NOAA active region 0375 and was located 9 degrees behind the east limb of the Sun. Flare footpoints were thus occulted from view by ~9000 km, allowing for a relatively unobstructed detection of emission from the associated coronal sources. Throughout the duration of the flare, a thermal hard X-ray source can be seen rising with a velocity of ~7 km/s above GOES SXI soft X-ray and EIT ultraviolet (304A) loops. During the impulsive phase of the flare (0237-0310 UT), a non-thermal source is additionally seen above 15 keV with a relatively soft power law spectrum with an index around -5. This non-thermal source is displaced from the thermal source by up to 10,000 km and shows greater variations on a time scale of tens of seconds. We will present total energy estimates and a detailed analysis of the source motions during the flare. We will also discuss implications for models that postulate above-the-loop-top sources.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFMSH22A0172B
- Keywords:
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- 7509 Corona;
- 7514 Energetic particles (2114);
- 7519 Flares;
- 7524 Magnetic fields;
- 7554 X rays;
- gamma rays;
- and neutrinos